Bravenet don't say you can do that because it is a total "no brainer". Bravenet are primarily providers of a general toolset for webmasters. Hosting itself is a very recent addition to that toolset.

What am I missing? If you have a domain name and hosting with Godaddy, why are you here at all?

I looked at the Godaddy hosting plans, and even the Economy plan gives you all the language support you can stand (MySQL, PHP, perl, etc..). For your own forum use you can use Simple Machines Forum — SMF, which is offered as an add-on. I would guess that SMF on your web site would be far more configurable than anything that Bravenet might have to offer.

Bravenet designs their tools so that they can be used with almost any web hosting. Their tools are hosted on Bravenet's servers, so all you really get is a link to the service. If your pretty good a web page design, you can make it appear to be from your site, but it's always hosted on Bravenet servers.

I recommend that you explore the offerings on the service that you already pay for, before you start looking around at other alternatives.